


Valency

by opposablethumbs



Category: Marvel, Marvel Cinematic Universe, The Avengers (Marvel) - All Media Types
Genre: Accidental Boners, Alpha/Omega, But also not quite, But not quite, Floor Sex, M/M, Nesting, Sex Pollen, To be fair everyone is kinda horny, it's a stucky story, the stony is accidental
Language: English
Status: Completed
Published: 2017-08-17
Updated: 2017-08-17
Packaged: 2018-12-16 14:23:03
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 8,797
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/11830563
Author URL: https://archiveofourown.org/users/opposablethumbs/pseuds/opposablethumbs
Summary: The team is contaminated by a mysterious chemical whilst raiding a Hydra base, and begin to have some unusual reactions.





	Valency

**Author's Note:**

  * For [NurseDarry](https://archiveofourown.org/users/NurseDarry/gifts).



> Betad by, and dedicated to, the floating vapour of wisdom and dead rodents that is [nursedarry](http://archiveofourown.org/users/NurseDarry/pseuds/NurseDarry). All hail.

Steve touches the comms switch on the dash of the Quinjet and signals the Tower. It only takes a few seconds before Bruce Banner’s face pops up on the HUD.

“Captain,” he greets, “you’re ahead of schedule.”

Steve nods, glances over his shoulder and into the darker main part of the craft’s interior. There, he knows, Nat is sat swaddled in blankets and Clint’s concern. As if on cue, he hears her growl ‘I’m fine’, and the archer backs slowly out of the shadows.

Turning back to the now rather concerned face of Doctor Banner, Steve shifts his weight. “Yeah,” he says quietly. “Bruce I don’t want you to…” Steve considers his next word very carefully, “...worry, but Natasha has taken a hit.” He sees Bruce’s fist clench on the console.

“She’s injured?” Bruce asks, voice tense and tinged with monster.

“No,” Steve hurries to assure. “Not exactly. The Hydra lab was filled with chemicals. One of the goons released one of the containers, she caught some of the spray. We put her through the basic decon back on the jet…”

“Tell me you didn’t decon her uniform.” Bruce scowls.

Tony, leaning in from the pilot’s seat, “Who do you think you’re talking to?” he quips.

For a moment it looks like Bruce is about to say something uncommonly rude, but he stops himself and simply snips out the word, “Cap.”

Tony huffs and returns to flying the plane. In other circumstances, Steve might congratulate Bruce on not rising to Tony’s bait, but he chooses to give the gamma scientist a full debrief instead.

“Nat went into decon and she left her uniform sealed in the hazmat unit. We’re bringing both her and it back to the tower, eta…” He looks over at Tony who raises two fingers. “Two hours,” Steve says, assuming that’s what Tony’s gesture means.

“Is she displaying any signs of poisoning, any skin discolouration or burns?” Bruce replies.

Steve shakes his head. “No. Until an hour ago, I’d have said all she had was a bit of a head cold, and she says she was feeling a little stuffy before the mission.”

Bruce’s jaw ripples and his teeth clench. “And now?” he asks.

Steve licks his lips. “She’s… acting strangely. Short fuse, kind of aggressive. Seems to see any authority figure as some kind of threat; she’ll only let Clint near her. And she keeps demanding we stop for cheeseburgers.”

Tony leans in again. “Which is totally my line,” he remarks, and Steve nudges him back out of the way.

Bruce, who thankfully no longer looks like a threat to the Tower’s structural integrity, pushes his glasses up his nose. “Do you have any idea what was in the container? Was it labelled, did it give any indication whether it contained chemical or biological materials?” He has to be addressing Tony with these questions, so Steve allows the seated man to answer.

“No, nothing on content. No markings: Hydra doesn’t really go all out for material safety. There was an environmental control on the unit, set at ninety-seven degrees, so I’m inclined to think biological over chemical, especially considering the lack of immediate visible insult.”

Bruce is nodding, taking in the science, making connections in his head the same way Steve does on the battlefield. “And what about dispersal, how far were the rest of you from where it happened?”

This is more Steve’s area. “It varies from a few feet to perhaps a dozen. Tony was closest. She was guarding him.”

“But Tony was in the suit?”

An embarrassed-sounding cough comes from beside Steve. “Well, no. They had a touch sensitive keyboard on their main computer so I needed my hands…”

“So if whatever it is is volatile, any of you could be exposed. And if it’s biological, there’s routes of transmission to consider. It could spread by touch, or take a respiratory route…”

“Yay,” says Tony, mutedly.

“Or it could be neither of those things,” Bruce concludes. He massages this temple for a moment. “I need you all back here as fast as possible so I can start to get a handle on this.”

“I’ve got the engines on redline, Bruce,” Tony says, but he’s serious for once.

“Good,” Bruce says, and logs off.

Steve turns to Tony, looks down at him. Tony’s face is a little flushed and his eyes sparkle moistly. Steve puts his hand on the other man’s shoulder and squeezes it gently.

“You okay?” he asks.

Tony nods, blinks and then a high-pitched sneeze catches him off guard. His eyes, now decidedly watery looking, widen.

“I can probably tease a bit more out of the engines,” he says.

Steve’s fingers tighten, feeling the tight play of muscles beneath Tony’s t-shirt. “Good,” he echoes quietly.

****

They’re back at base in one hour forty, by which time it’s clear that it’s not only Nat that’s been affected. Tony has to transfer landing control over to JARVIS because his hands are shaking. Even Steve, much to his surprise and Bruce’s consternation, is feeling out of sorts. His skin is warmer even than usual and he feels like he wants to scratch, but he isn’t sure where. His temper is running hot, too, and it’s as much as he can do to stop himself shaking Bruce and demanding he hurry the hell up fixing them. The flappy little examination gowns Bruce has made them wear isn’t helping anyone’s mood either.

In addition to Tony, Nat, and Steve himself, the mission personnel also comprised of Clint - who of all of them seems the least affected - and Bucky. And whereas Tony, and even Nat, are complaining loudly about being hungry, Bucky is a standing stone of silence. The only noise and movement he’s made since they disembarked the Quinjet has been the repeated calibration of his metal arm; the buzz of servos and the faint chink of the plates as they snap together. Steve recognises it as Buck’s way of staying calm, and guesses he’s feeling as clammy and stifled as the rest of them. But it’s not Buck’s way to complain, and Steve knows he wouldn’t anyway in the circumstances. This is only his third mission out with the Avengers; the third of his ‘opportunities’ to prove to Fury and the others that he’s no longer a threat. Steve knows how important this is to him, to fight on the right side of the line and do good after so many decades being forced to obey evil.

It’s important to Steve too, if he’s honest. He’d thought everything he had before the ice was dust, long swept away by everyone but him. Finding out that Fury’s grandfather had preserved his bike; that helped. Tony tracking down Peggy helped more, although it hurt at least as much. Bucky… Bucky had been nothing Steve could have prepared himself for. The two years after the bridge were a blur at times: the near-miss with the Ultron tech, telling Tony about Howard, telling Tony about _Bucky_. The months and millions spent tracking and hunting, and then more after they found Bucky, alone and confused in a warehouse complex upstate. But slowly he’d come back to them, come back to Steve. There are even times, admittedly rare, when Bucky smiles, and Steve can see his lifelong friend there again. Older in the eyes, but still so beautiful.

Steve swallows, his eyes drifting up and down the taut lines of Buck’s ever-ready body. So beautiful. It’s a thought he’s kept almost perfectly to himself for nigh-on eighty years. But with the way he is right now, nerves set alight and his stomach perched on a precipice, it comes to him again. He remembers feeling a little like this back before the War, on damp New York nights when the smell of salt and dirt came in from the river and he could hear Buck snoring softly. 

There’s an urge, a _desire_ , to kiss Bucky, to feel the hardness of his body and the pull of his sea-grey eyes. To taste him, to rub into his neck, his chest, between his legs, and just inhale. Maybe not even ‘just’.

Steve shakes himself free of the idea in time to realise he’s actually moved closer to where Bucky is leaning. He forces himself to step back, casting a worried look around the room, imagining everybody can tell the images warring in his mind.

Bruce alone catches his eye. “Everything okay, Steve?” he asks with quiet concern.

Steve nods, not quite trusting his voice.

“You need something?”

Steve almost groans. “No,” he says through gritted teeth.

Bruce nods and makes a mark on his clipboard. The scratching of the pencil against his paper has Steve clenching his fists.

“Okay,” Bruce says calmly. “I’ve determined none of you are in immediate danger. I’ve isolated the foreign biochemical present in all of your bloodstreams and I have a working hypothesis of what it does.”

The servos in Bucky’s arm whirr again.

“And what is that?” Tony says, more blunt than usual.

Bruce raises his eyebrow and runs his pencil down his pad. “You’re all displaying low-grade pyrexia, tachycardia, tachypnoea and increased sweating. I’d liken it to an infection except there’s no increase in white blood cells. Both Natasha and Tony are complaining of abnormal hunger and everyone is…” Bruce shuffles his feet, “understandably on edge.”

Natasha snorts. “You mean we’re ready to flip the fuck out if you don’t let us out of this goddam laboratory already?”

Bruce nods. “Yes. And that’s why I suggest you all get dressed and get out of my laboratory so that I can get to work understanding what is happening to you and finding a neutralising agent.”

“Thank God!” Natasha exclaims. “Eugh, you all _stink_ you know.” She narrows her eyes at Clint, stepping forward on her toes with a ballerina’s grace and a predator’s determination. When she gets within a few feet she stops and inhales deeply. “Except _you_ ,” she says. “The rest of you, I don’t know if I want to fuck you, eat you, or fight you, so stay away from me until this is done. Clint, I only want to do one of those things with you, so you’re with me.” She pounces, grabbing him by the hand and dragging him from the lab, medical robe and all.

“I have never been so afraid in all my life!” he calls back down the corridor to the remaining Avengers.

Bruce, who turned to watch her leave, returns his attention to the room.

“I’m going to assume Natasha’s eloquent summary goes fall all of you,” he says. “Enhanced sense of smell and sexual arousal on top of the aggression and appetite?”

Steve feels an extra flush in his cheeks. Tony stalks up to Bruce, takes the clipboard out of his hands, considers the top sheet and then tears it off; screwing it up and tossing the ball on the floor. “Bruce, you know that’s how we all feel, because I can _smell_ it on you.

Steve comes alert. “We’ve transmitted it to you?” he says, glancing about the room for all possible points of assault should Bruce start to go green.

“Transmit is the wrong word,” Bruce says. “Contaminated, yes. The biological molecule appears to only remain active outside the body for a limited period of time. Unfortunately, it looks like that time is about six hours, from my current model.”

Bucky shoves himself away from his leaning post, speaking up for the first time in over an hour. “So if you’re affected too, how come you’re still you and not the other guy. Hell, I could punch through a wall right now and I’m only half-monster.”

“And I’m so hungry, I would eat Thor’s cooking,” Tony confirms.

All three turn to face Steve, and as Steve looks between them, he spots a little twinkle in Bucky’s eye, a long-lost ‘fuck-you, pal’ kind of challenge that only exists between best friends.

“Cap?” Tony says with a smirk, “Anything to add?”

“Are you going to be okay?” Steve says, directing the question to Bruce and ignoring the sweet and peppery scent wafting from Tony alongside his attitude.

Bruce chuckles. “You know me, Steve. I’m always angry. And hungry for that matter.”

“And horny?” Tony says, twitching his eyebrows.

With a lot more restraint than Steve thinks he would of shown, Bruce turns on the smaller man. “I haven’t been able to have sex in over a decade, Tony. What do you think?”

Behind him, Bucky snorts. “Amateur,” he mutters.

“Can you find an antidote, Doctor Banner?” Steve says, shooting Bucky a scowl.

“Yes,” Bruce replies. He shifts his weight. “Probably. The molecule shows no evidence of decay once inside the human body, but there may be a way to make it inert. I’ll need to run some tests.”

“I just can’t figure out what Hydra would hope to gain from this,” Tony says, pulling his pants on. Steve absolutely doesn’t follow the snug slide of the denim as Tony tugs them over his ass.

Bucky all-but growls, a noise which doesn’t entirely help Steve’s current state. “Confuse and disorientate an enemy army,” he says. “Non-lethal punishment of their own troops. Direct mating behaviours in the general population…”

“Got it,” Tony says. “They’re creepy fuckers.”

Steve doesn’t correct him: there are very few words he would consider too strong to describe Hydra. “Whatever the reason, we’re apparently stuck like this for a while. I say we focus on not doing anything we might regret later while Bruce finds a way to help us.”

“Oh, but I’m so bad at avoiding things I’ll regret later,” whines Tony.

“We know.” Even Bucky joins in the chorus.

Bruce moves off to a console at the back of the lab.

Steve sighs. “Maybe just try and do something no-one else will regret later.”

Tony taps his fingers on his lips. “And if I order twelve sixteen ounce steaks, medium rare, for immediate delivery?”

“I might kiss you,” Bucky replies. A horrified look comes over his face. “I didn’t just say that.”

“No, you did,” Tony says smugly. “JARVIS, replay Sergeant Barnes’ last comment.”

The words ‘ _I might kiss you_ ’ echo through the lab.

“Definitely one for the bank,” Tony smirks.

Steve’s stomach clenches. He knows Tony is only joking, flirting on instinct the way he always does, but it feels _wrong_ in a way it never has before. The urge is in him to grab the pair of them and say ‘mine’.

“Steak yes, kissing no,” is what he manages to say. He tries to soften the gruff tone of his voice by turning it into a joke. “What would Pepper say?”

Tony’s face falls for a fraction of a second before he recovers. “She’s seen worse,” he says, carefully flippant.

Steve purses his lips. At the mention of Pepper, Tony’s scent had faltered. It’s curious how fast Steve has adapted to this new sensory input. Certainly, Nat’s assessment of ‘stink’ isn’t how Steve would describe it. Bruce’s smell isn’t pleasant, true, but Steve would never be so rude as to describe it in those terms. Tony and Bucky, though… the smell emanating from the pair of them is oddly… calming, in different ways. Tony’s sweet and peppery smell makes Steve think of wine and friends and fireplaces. Bucky is clean linen and warm bread. 

The sound of Steve’s stomach rumbling fills the lab. Bruce looks up from his papers and frowns.

“Tony, order the steaks,” he says. “And leave me to work.”

Without argument, almost as strange as his reaction to Steve’s poor attempt at humour, Tony pulls out his phone and puts it to his ear. He begins walking off down the corridor but not before Steve hears him say ‘Maurice, mon bon ami et mon genie culinaire…’

Steve and Bucky trail behind him, moving slowly.

“I don’t like this,” Bucky confesses, once they are out of earshot of everyone else.

“Me neither, pal,” Steve replies.

“You feel like the others?”

Steve nods. “Yeah. You?”

Bucky huffs. “Yeah.”

“You don’t have to do anything you’re uncomfortable with,” Steve reminds.

“I know,” replies Bucky, “But I’ll never be uncomfortable with you.”

Steve’s stomach clenches and his heart skips in a way it hasn’t since before the War. He licks his lips, barely daring to open his mouth to let his tongue sneak out. But Bucky saves him from embarrassing himself by speaking again.

“How long do you think it’ll be before the steaks gets here?”

“Not long,” Steve assures.

****

The kitchen looks like a tornado blew threw when Steve and Bucky get to it. What seems like the entire contents of the fridge - mainly in the form of empty packets and crumbs - is spread across the counter. Huddled in the very far corner of the room, Nat and Clint sit on the floor, surrounded by mounds of food; sandwiches, packs of jerky, and at least five jars of pickles.

Natasha lifts her eyes to glare at Steve and Bucky. “This is ours,” she growls. She sniffs at a packet of pastrami and then hands it to Barton.

Tony watches the exchange from the couch with apparent humour. “If that’s yours, are the steaks ours?”

“Try it, Stark,” Natasha mumbles around a mouthful of bread.

Bucky drops onto the other end of the couch, maybe two feet from where Tony is slouched. Steve frowns. His instinct tells him to sit between them, but with two empty armchairs flanking the chaise, it might seem a little strange. He takes the chair closest to Bucky.

“I wonder why she’s okay with Clint and not us,” Tony muses between them.

“They’ve known each other a long time,” Steve answers, equally hushed.

Tony purses his lips. “Maybe,” he says. “But she said he didn’t smell, whereas we all do.”

They fall into silence, Tony half-heartedly swiping at his phone and Bucky pulling at a loose thread on his sock. Steve waits for it; it doesn’t take a genius tactician to know what’s coming. It’s Tony, unsurprisingly, who speaks up first.

“So what do I smell of?” he asks.

Steve drops his head to his chest with the predictability of it all.

“Red wine,” he says without looking up. “With black pepper.”

“I smell _good_ ,” Tony replies smugly.

“Eh,” Bucky replies.

Tony scowls. “You’ve got something to add, Robocop?”

Buck shrugs. “I get the pepper,” he says. “But it’s not red wine. More like… over-ripe fruit? Kind of sickly, if you ask me.”

“No-one did,” Tony replies huffily.

“You _exactly_ did,” Bucky replies.

Tony huffs some more. “Well, at least I’m not made out of octopus.”

“What?” Bucky’s ‘what’ sounds more hostile, but as equally confused, as Steve’s.

“You smell like Tacoyaki,” Tony explains. “I mean, that’s not _bad_ exactly. As _street_ food goes…”

“Are you calling me cheap?” Bucky replies, turning in his seat to glower at Tony.

Tony looks vaguely nervous for a second and then throws up his hands, palm-forwards and placatory. “But filling,” he offers.

Bucky’s brow furrows, and Steve can almost hear him unpicking that response.

Smoothly, JARVIS enters the conversation. “Sirs, I just wanted to let you know that the delivery helicopter is now being unloaded. Doctor Banner has chosen to receive his in the lab, and yours will be with you within the next few minutes.”

“Thank fuck for that,” Bucky says, and Tony nods, both of them rushing into the kitchen to begin gathering cutlery and crockery and glasses. Steve watches them move, like a domestic ballet filled with grace and power. He’s surprised, in fact, by how smoothly they work together. While it’s Bucky’s third mission as part of the team, it’s his first with Tony. In the field, he’d actually noted their reactions to each other’s actions had been delayed, and was going to suggest extra training with the two of them. But as they dance in and out of each other’s path, passing items between them without word, Steve wonders if perhaps he’d let his own feelings cloud his judgement about their ability to work together.

Tony sets the table, first for three and then lays an extra two as Natasha growls deep in her throat. He’s still arranging the tableware when the steaks start to arrive.

“Gimme, gimme, gimme,” he says, snatching the first of the serving trays. He lifts the lid and the smell of hot fresh steak fills the room.

“Shotgun!” Bucky cries, vaulting over the island counter, and grabbing two trays.

“Hey! One at a time,” Tony cries.

Bucky meets him with a challenging smirk, putting one of the trays down on the table. “That one’s for Stevie.”

Bucky’s words send a pleased little shiver through Steve. He hasn’t been ‘Stevie’ for a long time. Tony, on the other hand, mutters something under his breath; his glower thoroughly displeased. 

The mood doesn’t last long, however, as another waft of meat hits them all, and suddenly they’re clamoring for seats again. Natasha saunters up, recovers two plates and takes them back to her corner.

“Aww, knees,” Clint grumbles quietly as she hands one to him where he sits on the floor. 

Bucky doesn’t stand on ceremony, diving straight in with his fingers. Tony watches him for a short second and then shrugs and follows suit. Steve almost makes it through his entire first steak before downing his knife and fork and joining them. Soon they’re onto seconds, and the noises they’re all making strike Steve as vaguely obscene. Indeed, he has to try very hard not to whimper as Tony slowly and quite deliberately sucks each one of his fingers clean of juices at one point. 

Steve forces his mind away from the thoughts he’s having. He and Tony worked this out long ago, agreeing that the easy path into one another’s bed was one they didn’t want to follow. And Tony loved Pepper, any fool could see that. Whereas Steve…

Bucky belches. “Well,” he says, pushing himself away from the table. “That filled a hole.”

Tony snorts, but before he can verbally respond, a holographic display pops up over the centre of the table. It’s Bruce, still pushing chunks of steak into his mouth as he calls.

“Brucie-poo,” Tony greets. “You’ve got good news I hope.”

Bruce swallows. “News,” he says. “I’m not sure how good it is.”

“Give it to us straight, doc,” Bucky says, leaning into the screen’s capture radius.

“I’ve figured out what the chemical is doing,” Bruce replies.

Steve frowns. “That’s… progress, isn’t it?”

“Progress, yes,” Bruce replies with a shrug, spearing another piece of steak and popping it into his mouth. “Now that I’ve identified what receptors in the brain are being stimulated, I can work on an artificial inhibitor for them.”

“Okay…”

“The area involved is deep in the rudimentary parts of the hindbrain. Severe trauma to that area is almost always fatal, so most of what we know of this comes from supposition and observation of lower primates.”

Steve drums his fingers on the table top. “And what have you observed?”

The noise of Banner clearing his throat comes over tinnily on the intercom. “Most social animals exhibit certain behaviours within their groups; broadly segregating them into what’s termed ‘alpha’ and ‘omega’ categories. Size and aggressiveness often define these roles, but there’s some evidence that pheromones - biochemical signals - play a part.”

“I remember the 80s,” Tony snorts. “Boardrooms used to stink worse than high school locker rooms. Never did a damn thing but make you cough.”

“It’s supposed,” Bruce continues, undaunted, “that early hominids displayed this behaviour, in a similar way to great apes. As humans evolved however, it seems likely that the areas of the brain that detected and processed these pheromones simply shut down to save on unnecessary energy expenditure.”

Steve nods thoughtfully. “And let me guess. Hydra have found a way to reactivate them.”

“Precisely. And that leaves us trying to reconcile sensory input that tells us to fight, feed and… uh… other things, with our modern intellect and social manners.”

“So a typical Saturday night,” Tony adds.

“Okay,” Steve says. “I can see how that might be used to keep an enemy off-balance.”

“So what we’re smelling is each other’s pheromones?” Bucky asks, gesturing between Steve, Tony and himself. 

Embarrassment suffuses Bruce’s cheeks. “Uh… yes. At least, we’re aware and responding to it for the first time.”

Bucky frowns. “But we all smell different to each other.”

Bruce rubs at the back of his neck. “It’s my… ah... hypothesis that alphas, as sexual competitors, would use their pheromones to repel each other, but be strongly attractive to omegas. Omegas would likely sense alpha pheromones as very attractive, but not be repulsed by the scent of other omegas. Based on my own reactions in the lab, I… think I’m an alpha. Tony, that would make make you an omega.”

“Aww, Bruce,” Tony cooes, “Did I smell good to you?”

“I was briefly _chemically_ attracted to you, yes,” Bruce corrects firmly. “That’s how I realised I was affected. Thankfully my higher brain function was able to resist your inimitable charm.”

“So what _about_ me an’ Stevie,” queries Bucky quietly. “What’re we?”

Bruce crosses his arms, weight swaying slightly from side to side. “I… ah... why don’t you tell us how you smell to each other?”

Bucky hangs his head. “He smells good.” His voice is small and strained and it makes Steve’s chest clench.

“I could’ve told you that,” says Tony.

Bucky looks back up, eyes narrowed. “Short-Stuff’s nothing special though.”.

Tony bristles; half-comedy, half-genuine insult. “I beg to disagree.”

“Alright,” Bruce says. “Working on the basis that suggests you’re an omega, hence your indifference towards Stark, whereas Steve and I are alphas.”

“I’m the pretty one of the pack,” insists Tony.

“You keep telling yourself that, pal,” Bucky replies, showing a large number of teeth.

“So what does that make me?” Natasha calls from the far side of the room. “I don’t particularly like the smell of any of you.”

“A lesbian?” Tony suggests with a lewd grin. She throws a bread roll at him, which he takes a bite out of, before miming ‘mine now’ smugly at her.

“I don’t think this is about sexuality,” Bruce says, his voice only a little sterner than usual. “Just sex. It’s likely that your reaction is different because you’re a woman.”

“So what, women don’t get to like sex?” she asks, a dangerous glitter in her eyes.

There’s a definite pink tinge in Bruce’s cheeks. “No, no, no,” he assures peaceably. “Perhaps the way you interpret pheromones just depends on the point you’re at in your... reproductive cycle.”

Tony rolls his eyes. “Just ask her if it’s shark week.”

Natasha picks up another, and last, bread roll, makes to throw it, then frowns and passes it to Clint.

“I should get back to it,” Bruce says.

Steve nods. “Agreed, Doctor.”

The screen goes blank and everyone spends the next few seconds of silence to eye each other up. At last Clint breaks the tension.

“Hey!” he says, tossing the roll between his hands. “I didn’t find out what _I_ am.”

Tony shoots him a wicked grin. “Well, there’s one way to figure it out.” He gets up and saunters towards the two assassins. Once he’s within a step of Clint, he stoops down and takes a deep breath.

“Huh,” Tony remarks as he straightens up.

“What?” Natasha growls, grimacing at the proximity.

“Barnes, get over here and smell Barton. You too, Cap.”

Steve puts a hand out, stopping Bucky from moving. “Nat,” he asks, “Are you okay with us coming nearer?”

“For science,” Tony adds.

“Eugh,” Natasha says. “Just… yeah, give me a minute.” She plucks the bread roll that Clint has been toying with out of his hands and holds it against her nose. “Yeah, go for it,” she says, voice muffled.

Steve is aware his hand still rests on Bucky’s chest, the warmth of Bucky’s skin radiant against his palm. He coughs. “Okay,” he says. 

Bucky smells Clint first, looking puzzled as he pulls away. Steve hesitates for a second and then leans in, taking a sharp inhalation. What he smells is… nothing. Well, not nothing. Just nothing either inviting or offensive. At most, it’s a warm milk scent

“Is everyone done sniffing me?” Clint demands indignantly.

“Yeah,” Natasha agrees, wafting them away with her free hand. “Shoo.”

Retreating to a safe distance, Steve leans against a counter. Bucky and Tony join him, flanking him either side.

Natasha removes her makeshift facemask and takes an experimental breath. She wrinkles her nose. “Acceptable,” she states.

“So?” Clint asks.

“Eh,” Tony says.

“Maybe he wasn’t affected,” Bucky suggests.

“No,” Tony replies, “I could definitely smell something. Marshmallows, maybe. But it wasn’t strong. Steve? Any urges to report towards Barton?”

Steve shakes his head, partly to answer Tony and part because _what is his life_.

“Weird,” Tony remarks. “What makes Barton different to the rest of us?”

“How long ya got?” Bucky suggests.

Tony’s eyebrows twitch. “About seven inches, how ‘bout you?”

“Oh my god,” Natasha says. “You two are worse than kids.”

“Kids,” Steve echoes thoughtfully.

Tony stops the indistinct bickering going back and forth between him and Bucky. “What’s that now?”

Steve straightens. “Well, Barton has kids, doesn’t he?”

“And we all know kids ruin your sex life,” Tony agrees.

“Hey!” Clint calls. “Me and Laura still…”

“Enough, sweetie,” Natasha says quietly, patting his knee.

“JARVIS,” Tony says, “connect me to the lab.”

The screen comes live and Bruce looks up harriedly into it. “Tony, it’s only been five minutes. It’s going to take at least half an hour to separate out these proteins.”

“Yeah, no. I just had a question. Is it possible that having kids means Barton wouldn’t produce pheromones?”

“No,” Bruce says, brusque and distracted. “If anything it proves that he’s virile.”

“Yeah it does,” Clint interjects.

“I suppose him having a wife could affect it,” Bruce continues. He’s pipetting something into vials as he speaks, not looking into the screen. “A proportion of animals breed monogamously. It’s possible that being in a stable, long-term relationship causes his pheromone production to drop off to negligible levels.”

At his side, Steve feels Tony stiffen. 

“So anyone in a serious relationship shouldn’t smell like we smell?” the smaller man asks, his words as tight as his posture.

Bruce shrugs. “Possibly. It’s all theory. Now… I really have to get on with this.”

“Yeah, sure,” Tony says. There’s no play in his voice now, and as he dismisses the holographic communicator Steve thinks he sees a moist glimmer in his eyes that wasn’t there before.

Tony turns his back on all of them. “Well, while Bruce gets on with that I’m going down to my workshop.” He stalks out of the room, the hard soles of his shoes clacking slightly on the Italian marble.

“Okay,” Clint says once Tony has cleared the room. “I’m not Mister Sensitive, but did that strike anyone else as weird?”

“It’s Stark,” Natasha says.

But Steve isn’t convinced. He looks at Bucky.

“You should go talk to him,” Bucky says.

Steve stops himself short of asking if he’s sure, because there’s a creeping distance in Bucky’s eyes. Instead he says, “Do you want to come with me?”

There’s a hesitation and then Bucky shakes his head. “He’s your friend,” he says quietly.

Steve reaches out, takes Bucky’s hand. “So are you,” he replies.

Behind them, Natasha clears her throat. Steve realises what he’s done, the intimacy of the gesture he’s just initiated. He pulls his hand back, aware of a little resistance from Bucky’s side.

“I, uh… sorry. This Hydra stuff....”

“Yeah. Yeah, of course,” Bucky agrees. “Now… Stark?”

Steve nods, first at Bucky, then at Natasha and Clint, and goes to find Tony.

****

Tony isn’t that hard to find. He’d said he was going to his workshop, and that is indeed where Steve finds him. It’s not so much Tony’s word however that leads Steve into the lower levels of the tower, but the vibrations and wall of noise that gradually amplify the further towards the basement he gets.

Stepping out of the elevator and into Tony’s workspace, Steve spots Tony among a pile of spares. He’s stripped his shirt off to wade amongst the greasy parts, leaving only an undershirt covering the welted scar on his chest. He’s already lost to whatever process he’s got in mind, oblivious to everything but the task in hand and the blanket of sound surrounding him.

Steve takes a few paces inside and then stops, frowning. “JARVIS?” he yells. “Enact the snooze protocol.”

Long ago, Steve learned that no one but Tony had the permissions to turn his music completely off, but that JARVIS would allow them to change it from one genre to another. Of those, however, only the snooze protocol actually attenuated the volume of the music played, taking it down to a volume at which Tony could sleep and, pertinently, one at which others could talk.

The switch does stir Tony from his rummaging. He lifts his head, eyes dark and wary, and rubs his nose with the back of his wrist.

“Cap,” he greets.

So it’s going to be like that. “Everything all right?” Steve replies.

Tony shrugs. “Always,” he says.

“Just… you ran out of there a little fast.”

“I didn’t run,” Tony points out, face carefully assembled in an expression of neutrality. “These shoes are Italian leather. No one runs in handmade brogues.”

Steve comes a little closer, close enough that he can pick up the rich fruit scent that comes from the other man. It’s reassuring, calming. Undeniably attractive. Somehow, in just the few short hours they have been afflicted with this extra-sensory information, Steve has come to accept it as easily as his sight or hearing. In with the aroma of autumn, he can now detect a slight, wavering scent of spice, something gingery that makes Steve’s nostrils flare with displeasure.

“Tony,” he scolds.

Tony drops his head. “What do you want?” he asks.

Steve moves close enough to reach out, placing a hand to Tony’s shoulder. “An explanation?”

“What do I smell like to you?” Tony asks, quiet and restrained in a way Steve has seldom heard him.

Steve licks his lips. “I already told you,” he says.

Tony lifts his eyes. “Exactly,” he says. “I smell. I have a scent that you and Bruce, and even Barnes can detect.”

And then it hits Steve. “And you shouldn’t, because Barton doesn’t. Because of Pepper.”

Tony pulls pistol fingers, misery clear on his face. “She was talking, just before this mission, about taking a break. I just… I didn’t think that meant we were broken.” He picks up two machine parts, one in each hand. “This I can fix. But me and Pep? That I’m just not sure what’s wrong.”

There are blinking tears in Tony’s eyes, and Steve can’t stop himself. He pulls Tony into an embrace, feeling the way Tony startles at first but slowly relaxes into it. There are damp spots on Steve’s shirt where Tony’s face is buried into his collar, and as he rubs his hands in small circles against Tony’s back, he slowly becomes aware of huffing warmth and cool their too. Tony is smelling him, inhalations making the damp spots grow cold and exhalations warming the fabric near his neck. 

And it’s so natural to draw in a breath of Tony, too. To relish the scent of him, and for Steve to hear the words _mine, mine, mine_ in the rhythm of his pulse. The side of Tony’s neck is sweet caramel, and Steve wonders if it would taste that way too. He wonders what other parts of Tony’s skin might taste of, whether his crotch might hold the smoke and salt of butterscotch, and whether Tony would melt the same on his tongue. Then he realises that Tony is huffing again, but more vigorously this time, shoulders shaking. Steve pulls back to stare at his face and sees that Tony is _laughing_.

“I’m so glad you’re the one with the inappropriate erection,” he chuckles.

Steve stumbles back, virtually falling over his own feet. Oh God, Tony is right. He’s notably and _noticeably_ hard, straining against the confines of his pants. He was supposed to be comforting a friend and instead he’s getting off on something as simple as a hug.

“It’s… it’s the stuff,” he stammers. He swallows, attempting to regain some composure. “This thing that’s been done to us, we don’t fully understand it. Bruce is only guessing. We don’t really know what it means. You and I…”

Tony offers him a wry smile. “You and I could be spectacular, but we both know there are people in our lives who mean more to us than just great sex.”

“Pepper,” Steve says, grateful for the lightness seeping back into Tony’s voice.

“Barnes,” Tony counters.

Steve straightens, coming to attention. “Bucky is just a -”

“Really hot guy you’ve dedicated your life to?”

“Friend,” Steve counters, belatedly finishing his earlier statement.

“Uh huh,” says Tony. “You realise he came within seconds of fighting me over you a half-dozen times this afternoon.”

“It’s the same for him as it is for you. And for me. It’s all just chemical.”

“Bullshit. If chemistry had all the answers, why would we need physics?”

Steve studies Tony’s face, the lines around his eyes. “Okay,” he says after a heartbeat, “You’ll call Pepper?”

Tony nods. “You’ll talk to Barnes?”

Steve knows better than to do anything other than agree. “Sure,” he says. “The next time I see him.”

Tony chuckles again. “Just try and keep it in your pants til then, Rogers.”

Steve feels his cheeks heat. “I’ll do my best,” he says, and scurries his way back to the elevator.

****

Steve rides the elevator from the basement, bypassing the common areas, and straight up to his personal floor. Tony’s words echo in his mind and Steve can feel the sense of them, the indisputable honesty. He wonders if that’s a side-effect of the chemical as well: the inability to fool oneself when you can literally _smell_ the truth. 

He and Bucky… well, they’d fooled about as kids. Or when they were a little older than kids, if truth be told. But the war had put a stop to that. Nothing like being caked in mud and three-day-old blood to put you off a quickie fumble. Maybe once or twice straight after Azzano they’d come close to something, but it’d always been tinged with the can’t-go-back bitterness of stolen innocence. 

The twenty-first century is not an innocent time, however. Steve had figured that out within weeks of coming out of the ice. Not that there was anything new in what went on, oh hell no, but people were just so much more open about it. You could step out with your best gal, your best guy, both, neither, somewhere in between… the possibilities seemed endless. And when your best friend from eighty years past struts back into your life, you start to think maybe anything can happen.

But there’s still that bitter taste to it all, he can see it in the depths of Bucky’s eyes, and that’s why Steve hasn’t pressed the matter. Or mentioned it, even. With Bucky now living with them all at the Tower, there’s been opportunities, of course, but none that felt… right.

He shakes his head as he presses his thumb against the entry pad to his suite. Tony may have a point about talking to Bucky, but when they’re contaminated by some chemical agent that’s making them all kinds of hopped up probably isn’t the time either. It’s more like the time to shut yourself in your room, read a book, maybe engage in a little… stress relief for the lingering problem in one’s pants. The big brains will do their thing and at least he can’t be tempted by any of the sights and especially _smells_ of his team members if he’s alone. 

The door clicks, indicating the security has been deactivated, and he pushes it open.

“Hiya Stevie.”

Steve stops in his tracks. “Bucky?” he asks, blinking at what is indeed Bucky, sitting on his floor, surrounded by cushions. “How did you…”

Bucky looks at him like he’s stupid.

“Oh, yeah. Highly trained assassin, locks not really a problem, right?”

“Right,” Bucky confirms.

“So skipping past the how, how about the why?”

At that, Bucky’s brow knits. “Is it a problem?”

“No,” Steve says, a little too hastily. “No, just unexpected.”

“I figured when you were done with Stark, you might want some company.”

“Sure,” Steve says, pasting on a smile and walking towards Bucky in what he hopes comes across as a casual way. He stops next to the bare sofa, and peers down at the puddle of pillows and super-soldier at his feet. “Got something against my couch?” he asks. He looks past the mound to his stripped bed. “And blankets?”

Bucky shrugs, and averts his eyes.

Steve sighs and gets down on his haunches before plopping to the floor beside Buck. “Come on,” he says. “Spit it out.”

Bucky looks back, fingering the seam of one of the cushions. “I wasn’t happy about you going running off after Stark.”

“You said to go!”

“I _know_!” Bucky replies, throwing up his hands. “This stuff, it doesn’t make a lot of sense. I know you’re his pal, but once you’d gone I just felt…”

“Jealous?” Steve suggested quietly.

The smile Bucky gives in return is mostly grimace. “Stupid, right? Not like I peed on you and made you mine.”

“First, please do not pee on me,” Steve says, offering a softer smile as response, “and second…” He takes Bucky’s hand and gives it a reassuring squeeze. “It’s not stupid. We’re all out of sorts.”

“It ain’t just that, though,” says Bucky, shaking his head and making his long hair swing with the motion, “I _want_ to be here.”

Steve licks his lips. “And all this? Some kinda fort like when we were kids?”

Bucky snorts. “This, I don’t even fuckin’ know where to start. Like, what do I care about soft furnishings, and suddenly all I can think about is whether I’d be better sticking with chenille or whether cotton twill would make a better…” Bucky trails off, a mottled pink flush climbing up his neck and his hand, still in Steve’s, is damp with perspiration. 

Steve tugs on it, drawing Bucky’s hand closer to him. “Better what?” he says.

Bucky snorts, shaking himself free of Steve’s touch. “A better fucking _nest_ , Steve. I’ve built a goddam nest in your suite.”

“A… nest…” Steve drawls.

“Yeah,” Bucky replies. He laughs softly. “Since I got back, since I came here to live with you and Stark, and Natalia and the others, I’ve been thinking about how it used to be with us. I figured maybe it was just nostalgia, me wanting to be who I used to be. And you said nothin’, so I figured it was just that.”

“Bucky,” Steve murmurs.

Bucky shakes his head to cut Steve off. “But then we got hit with this stuff,” he continues, “and suddenly I’ve got proof that we still go together, and it’s all I can do to stop from kissing you...”

Steve is dazed, barely hearing the words Bucky is saying in favour of the other sensory details flooding him. The softness of the furnishings surrounding him, the tingle of proximity prickling through his nerves. Bucky, so close, his skin catching the evening light that filters in from the window, making it seem like he’s golden. And the scent, clean and comforting, wreaths in with the familiar, typically unnoticed smell of his own property, and changes into something new. Again, his pulse is thrumming fast and hard in his veins, that rhythmic beat that says _mine, mine, mine_. But now, in each silence between beats, he hears an answer: _yours, yours, yours._

“What?” Steve asks blearily, belatedly processing Bucky’s words.

“Jeez, Stevie, were you always this slow or…”

Steve makes his move, shoving Bucky back against his cushions, his _nest_ , and straddling the other man’s broad hips. Bucky cants up into him, making it absolutely and totally clear that there is nothing one sided in this action. Leaning in, Steve kisses Bucky, firm and messy. He tastes like the cinnamon red hots they'd get at the corner drug store, sweet and spicy all at once. They kiss each other breathless, hard and desperate, aching with the need for more. They part only so much as required to shed their clothes, and once that’s done they’re back together, skin meeting skin. Just like it always had been. Just like Steve had hoped it could always be. He looks down at Bucky; hair splayed out in a dark halo around his head. His lips are pink and swollen, and they twist into a satisfied, if a little smug, smirk.

“Hail fucking Hydra,” he says.

Steve frowns, a sudden tightness in his stomach. He cups the angle of Bucky’s jaw with his palm, stroking his fingers over the swell of Bucky’s cheekbone and down to his lips. “Not even as a joke,” Steve says.

Bucky huffs and reaches up with his metal arm, curling it around Steve’s neck and pulling him in for another kiss.

****

Night has fallen by the time they collapse apart, Bucky flopping off Steve’s sweat-drenched body and onto the messy sprawl of cushions. 

“That serum, man,” Bucky pants, his voice hoarse from exertion. “Good thing we did it on the floor, think we’d have broken the bed.”

Steve laughs, broken, staring up at the flickering shadows on the ceiling. Hell, he’s not felt this wrecked since before the serum. He feels Bucky shift, moving closer again.

“Jeez, no more, Buck,” he says.

“Shut up and let me cuddle you,” Bucky replies, tucking himself in under Steve’s arm.

They lie like that, warm and not a little sticky, for some time. Steve can hear from Bucky’s breathing that he’s not asleep, just still and silent against him. A flutter of apprehension begins in Steve’s stomach.

“Hey,” he says quietly. “What’re you thinking?”

There’s a pause, and Bucky wriggles slightly, tucking his foot under Steve’s calf. “I'm thinking that if these cushions were cotton, we could just put them in the wash. We're gonna have to get these ones dry cleaned.”

“No,” Steve says, craning his neck so he can look down at Bucky. “I mean… do you have any regrets. That aren’t upholstery related, I mean.”

“Should I?” Bucky asks.

In the silence that follows, Steve becomes aware of a soft ping coming from his desk. He presses a kiss to the top of Bucky’s head and then shuffles himself free of the embrace. Bucky whines and in the dim light Steve sees him scrunch up his nose.

“I’ve got a message,” Steve says. He crosses to his desk and flops down in his chair.

Bucky sits up, the light of the city bouncing off his metal arm. “Play it, then.”

Steve presses the touchpad to accept the message. 

It’s Tony. “ _Hey Cap. Bruce has done his thing, we’ve got the cure. We’re all heading down to the lab to get a shot, join us when you’re ready. And if you manage to rustle up Barnes on your way, let him know too?”_ There’s a wink in Tony’s voice that doesn’t show on his face.

“Wiseass,” Bucky grumbles, standing and scratching at the rippled pad of his stomach. “Steve, tell me I’m the prettiest of the pack.”

“Bucky, baby,” Steve says, suppressing a smile. “You’re the prettiest of them all.”

Bucky chuckles, satisfied. He walks towards Steve, that dangerous sway in his hips that Steve would love to do something about in about twenty minutes and after some serious rehydration. He comes to a stop behind Steve, placing his hands on Steve’s shoulders. The flesh is warm, but the metal is cold. The familiar, and the unfamiliar, like so much that has happened today. He leans back, head cradled by Bucky’s abdomen. He closes his eyes and inhales, the smell of sweat and sex mingling with the chemicals between them. He feels Bucky sigh, his stomach rising and falling. He gives Steve’s shoulders one last squeeze and then steps back.

“Come on,” he says. “Let’s go get fixed.”

****

“Oh, Captain my Captain,” Tony greets when Steve and Bucky arrive in the lab some twenty minutes later. “I know I said take your time…”

Steve rubs the back of his neck. “Yeah, we… ah…”

“Oh, we can tell,” interrupts Widow.

A flush prickles in Steve’s cheeks. “You can… smell it?”

“Nope,” Natasha replies. “We got cured. But the pair of you are positively _glowing_.”

Clint saunters up, passing them both drinks. “Speaking of which, you were safe right? No chance of pregnancy?”

“Pregnancy!?”

Clint nods. “Sure, Hydra sent us wacky in all sorts of ways. After you left, Bruce figured out they fiddled with our reproductive capabilities, too.”

Bucky is staring wide-eyed at Steve, and Steve feels more than a little boggled himself. With their serums guaranteeing they carried no nasty bugs, condoms had seemed unnecessary. Contraception, for obvious reasons, hadn't even been part of the discussion. But now Clint is telling them it's possible, and the idea of one or both of them - god knows how it would work - getting pregnant…

It’s only Bruce’s appearance, a needleless syringe in his hand, that halts Steve’s spiral into panic. 

“Pay no attention to these children,” he says. “They’ve been cooking this up since you and the sergeant didn’t respond to their call.”

Steve looks between all the other faces in the room. Clint has a wide grin plastered on his pie hole, and Natasha is hiding her own smirk behind her hand. 

Tony claps a hand to Steve’s bicep. “I see you took my advice.” 

Beside them, Bucky grumbles something. It sounds very much like it includes the word ‘assholes’.

Bruce lifts the syringe into Steve’s line of vision. “Ready?” he asks.

The flutter in Steve’s stomach is back, and he glances over to Bucky. “I… think so?” he says.

Not totally insensitive, Natasha pulls Clint and Tony away with her to examine a computer panel on the far side of the lab.

“You okay?” Steve asks once the others are out of earshot.

Bucky’s jaw sets tight. “Do it,” he grunts.

Bruce frowns at the brusque tone in Bucky’s voice, but lines up the jet injector to the man’s flesh bicep and depresses the trigger. 

Bucky closes his eyes as the liquid hisses into him. “How long..?”

“Not long,” Bruce says. “The delivery system is fast, and it only takes a few minutes for the antidote to pass into the bloodstream.” He twists the head. “Cap.”

“Sure,” Steve says, eyes flickering over the tense lines on Bucky’s face. He barely feels it as the cure is propelled into his body. He shifts closer to Bucky. He can still smell him, that sea and smoke scent that Steve will forever now associate with this man he loves. He wonders for a second if the cure might not work, but then…

“It’s gone,” Bucky whispers. He opens his eyes and turns to Steve. “You?”

Steve nods. “Kind of nice while it lasted.”

There’s a slight tremble through Bucky’s body, only perceptible because they’re standing so close, and Steve hears the arm recalibrating, a sure sign of disquiet. “Yeah,” Bucky agrees. He’s already turning to leave the laboratory when Steve catches his hand. He looks over his shoulder at Steve, with hopeful eyes.

“Buck, what happened between us…”

“I get it,” Bucky replies. “Hydra had us all gee’d up, and you and I’ve got history…”

“We’ve got a future, too.” The words are out of Steve’s mouth before he really considers them, utterly sincere in their presumption. “If… if that’s what you want.”

Bucky blinks, taking a literal step back as he turns to face Steve once more. “Us? Together?”

“Maybe we can ask Tony to reinforce the bed.”

Bucky looks like he’s going to say something, but is torn between heartfelt confession and calling Steve a jerk. Steve decides to save him the choice by leaning in and planting a soft kiss to Bucky’s lips. The faint taste of cinnamon there is a memory, but no less sweet and promising just as much fire. When he pulls back, Bucky is smiling.

Looping his arm around Bucky’s back and pulling him into his side, Steve propels them towards where the others are waiting and absolutely not gossiping about horny grandpas. 

“Hey, Stark!” Bucky calls as they get close. “We’ve got a favour to ask.”

**Author's Note:**

> When I'm not writing things like this, I'm talking about writing things like this on my [tumblr](https://opposablethumbs-on-aO3.tumblr.com/). Want to discuss fan theories or ideas? I'm your thumb!


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